To begin with, this is the defining comparison. If you attain a C in EFL, it is considered a better score than an A* in ESL. EFL is far more worthy as a subject and carries more credits. However, it is much harder as a subject.
Now as for King's University, the cost is extremely high for that of a foreigner.
This should ne suffice to answer your queries about KCL.
However, you must also take into consideration the expenses of an apartment, also food etc. And this will make the stay even more expensive, I remember a friend of mine saying that the cost of living surpasses the tuition fees.
I would not suggest England as a place for Undergraduate study, because quite frankly the quality of the Education provided has taken heafty blows after the financial crisis. I would rather suggest Canada or America, which is welcoming of foreign students.
After studying in the UK, you will not get a job there, you need to return back home. So, UK is pretty much the worst place for further study.
